My experience rebuilding 4l60E and observations.

I'm a retired, curious guy with some time on his hands. So when my 95 Blazer, 4X4 experienced some transmission problems I decided to take a shot at rebuilding it. Original symptoms were, serious slipping when starting out in "OD." I bought the ATSG manual and a DVD, along with a "Master" rebuilding kit. Also, a new Torque Converter. All via the internet. Harbor Freight Tools supplied the transmission jack. All costs were around $350.00. Getting the trasfer case and transmission out of the vehicle was pretty time consuming, working on my back. Vehicle was up on 4 ramps so I had plenty of room. I learned a lot. Got it out and begin tearing it apart. Found no metal in pan, etc. Following the DVD, I really didn't really find anything wrong. Clutches were worn but certainly not unusable. Filter was very dirty. These things aren't as complicated as you might think and can certainly be rebuilt if you have the time. Anyway, reinstalled it and had the same exact problem. Being the stubborn guy I am, I took everything out again. More time....
Reading about my problem on the internet I decided that the "Input Sprag" was probably defective, as the vehicle performed properly when starting out in "1" vs "OD", so I thought. Tore the transmission apart again and replaced the Input Sprag, which looked OK. Of course MD advised me not to do this without first checking any stored codes, pressure, etc. Check Engine light had never been on. Being the knuckle head that I am I did not take his advice. Anyway, put it all back in and still had the same problem. Took it to my transmission guy and he advised me that it was in the "Limp" mode. Starting out in 3rd vs slipping. I had checked the fuse by the way and it was good. He advised that 12V comes from the ignition switch and is not fused. Hard to believe. Anyway, it is at this shop and I will advise of the final problem.

This whole thing was not about money, I could afford to have it repaired. I just wanted to see if I could do it, and "de-mystify" these auto transmission things. It was an experience that was worthwhile, and I learned a lot about how these things work. Pretty ingenious....but not that complicated. If it had been a hard part, like a planetary, etc. I would have been successful. If it is an electrical problem I'm going to be Pi**ed. I'll let everyone know the final outcome.

Lynn Wagoner
Yukon, OK

Interesting.
Let us know how it goes.
Good Luck

Sorry, I said "MD" in my narrative instead of "MT." Of course it was MT...

No problem.

Got a call from the transmission guy today. He stated that he had fixed it by replacing all of the solenoids. Does this sound right? I had ohmed all of the solenoids as part of the rebuild......

If it is fixed that sounds good to me.
Replacing all may or may not have been a little overkill.
But a lot of problems with the solenoids and also wiring on them.
When you pick it up ask him how he found the problem or what code no's it was setting.
Post back code No's
Good luck

OK, evidently he only replaced the "B" solenoid. He wasn't there when I picked up the vehicle but one of the hands told me that the codes indicated that it had a solenoid problem. Check engine light never came on before. At any rate, it is fixed. I feel pretty good after completely rebuilding it...at least it shifts really good, etc. As stated, I had "ohmed" all of the solenoids and they came back within specs. I guess the coil could be OK and the solenoid still not work physically. Thanks for the help MT.

You are welcome and thanks for posting back how it went and the fix.
Glad all is fixed and well now.
Yes sometimes the ohm out test and the check engine light does not catch everything.
Sounds like you found a good transmission mechanic that got right to the problem.
It should be good for a lot of miles now.
Remember to drop pan and change the filter when it is due for a change.
Good Luck

Please let me know what the outcome is. It seems I'm experiencing a similar experience. I've been informed of this limp mode. But it doesn't seem to be starting out in 3rd.?? Maybe I just can't tell. I do know I do see 1st and 2nd then it slips and I'm not quite sure if it is making it into 3rd. I'm hesitant to replace any solenoids if it is in the ignition or somehting. Please let me know and best of luck to you.

Hello Calvin22. I actually didn't know it was starting in 3rd....I thought it was severly slipping in 1st. As MT2500 advised me from the beginning, I would encourage you to have someone read the codes. Evidently the transmission stores malfunction codes that can be read. I asked the transmission guy how he knew one of the solenoids was bad and he advised that the codes told him of a bad "B" solenoid. I could have saved a lot of work, but I wouldn't trade for the experience of rebuilding the transmission. Good luck to you....

Lynn Wagoner

Calvin22
Ever transmission is usually a different problem.
Even different years have different problems.
Hard to compare one to another.

If you are having problems first get a transmission capable scanner on it and read out data and code and go from there.

On yours if you need help on it Best to start a new thread and someone will help you.

Give all information like year and model and mileage and engine and transmission and 2 or 4W and transmission service history and any codes or check engine lights and codes.

And always check fluid level and condition first thing.